Web7 apr. 2024 · 1. You can use $facet in an aggregate pipeline like this: $facet create "three ways" where in each one filter the values by desired key (A, B or C). Then in a $project … WebThis will count all documents in the collection. The CountDocuments method returns a long value that represents the count of documents in the collection. We can assign this value to a variable named count in this example. You can modify the filter to count specific documents based on the values of certain fields.

$project (aggregation) — MongoDB Manual

Web6 mei 2024 · MongoDB’s aggregate () function may count several fields. As a result, the fields are counted using $count. Below is an example where a timestamp is utilized for only one entry. Some documents can be saved in the student collection in this example, and you can use the find () method to see how many documents you have. Web21 jan. 2024 · I'm a MongoDB noob and I have a MongoDB collection with millions of documents, each with tens of keys (average ~ 60, large variance) from a set of around 100. I'd like to get a count of each key across the entire collection. For example, if the documents in the collection were: hoover allergy powerhead replacement

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WebQuite possible if using MongoDB 3.6 and newer though the aggregation framework. Use the $objectToArray operator within an aggregation pipeline to convert the document to an … Web15 sep. 2014 · Mongodb aggregate (count) on multiple fields simultaneously. { "_id" : "someuniqueeventid", "event" : "event_type_1", "date" : ISODate ("2014-01 … Web10 dec. 2012 · 4 Answers Sorted by: 11 Iterate over the entire collection, and find the entire number of fields there are Now you can utilise aggregation operator $objectToArray ( … hoover alignment minneapolis mn